1. Field of the Invention
This invention relates generally to the field of protein biochemistry and more specifically to epitaxin, which is a cell motility factor.
2. Background Information
Cell migration is regulated by various extracellular signals at different molecular levels. Cell-substrate adhesion provides an anchorage that allows moving cells to derive traction and cell-cell adhesion and intercellular junctions act to restrict the movement of cells by binding them to neighboring cells. However, the cellular factors that signal a cell when and where to move only now are being identified.
Various cellular proteins such as cytokines can act as motility factors, which regulate cell migration. In general, these cell motility factors can direct particular cell types to a region of inflammation or an area of wound healing. Normally, the migration of specific cell types is tightly regulated. However, various cancers are characterized, in part, by unregulated cell migration, which can result in tumor cell invasion and metastasis. The unregulated migration of tumor cells suggests that cell motility factors can have a significant role in tumor cell invasion and metastasis. Thus, the identification of cell motility factors that act on specific types of tumor cells can provide a means to intervene in the process of tumor cell invasion and metastasis.
Several cell motility factors recently have been described. However, with the exception of scatter factor (hepatocyte growth factor; SF/HGF), the motility factors thus far identified primarily direct the migration of non-epithelial cell types. Unfortunately, nearly 90% of human malignant tumors arise from cells of epithelial origin.
Thus, there exists a need to identify motility factors that can control the migration of a wide range of tumor cell types, including tumor cells of epithelial origin and, therefore, are useful for reducing or inhibiting the invasiveness or metastatic potential of the tumor cells. The present invention satisfies this need and provides additional advantages as well.